SOUTH BEND, Ind. — Just like that, the tumble down a slicked cliff ended.

Notre Dame won a football game on Saturday. Pretty emphatically, too, a 31-13 dismissal of No. 15 Michigan State that probably closed whatever gate to Hades cracked open locally over the previous few weeks.

It wasn't vindication. The Irish are still 1-2 and a fair bit away from a worthwhile season. But it was affirmation, in that Notre Dame now knows what it can accomplish when it doesn't agitate a tire fire with turnovers and penalties and general malaise and instead responds with some vigor.

And it was a win. A deeply, profoundly, utterly necessary win.

"I'm elated to get the win," Irish defensive end Ethan Johnson said. "We really needed it, we did. I mean, 0-3 is a terrible place to be. I've never been there before, and I thank God I've never been there before and I won't have to be."

Notre Dame avoided that via another auspicious start, a newfound resolve to weather the standard-issue miscues (three more turnovers Saturday) and a defense that stuffed Michigan State into a broom closet and feasted.

The rough-and-tumble Spartans (2-1) accrued 29 net yards rushing, forcing them into an unseemly 53 pass attempts. While quarterback Kirk Cousins threw for 329 yards, he also was harassed with two sacks, 10 hurries and eight pass breakups.

"That was the whole message: Everybody do your job, be where you gotta be, and do it with ill intention," said linebacker Manti Te'o, who amassed 12 tackles. "We were trying to send a message all game."

On a macro and micro level, this was mostly about response. Third-degree burns from the first two games of self-immolation suggested Notre Dame hadn't done such a terrific job of that.

But on Saturday, a Tommy Rees fumble was answered with Irish freshman Aaron Lynch forcing a Cousins fumble on the next series. The defense held Michigan State to a field goal after a Rees interception, and then freshman George Atkinson III went 89 yards for a score on the ensuing kickoff for a 14-3 lead early.

Cierre Wood and TJ Jones touchdowns extended the lead while the defense held firm. Then in the fourth quarter, after a muffed punt return gave Michigan State a sliver of hope down 28-13, Irish cornerback Robert Blanton intercepted a pass and returned it 82 yards to set up a game-sealing field goal.

"We stressed all week you have to make your own luck, and we did," Irish coach Brian Kelly said. "They weren't lacking confidence, but sooner or later you gotta get paid. You gotta be validated in what you do."

Echoed safety Harrison Smith: "To be honest, I think this is something we really needed. Just that first step to get things going."

So, after a last defensive stand, Johnson karate-kicked the air jubilantly.

After the final horn, receiver Theo Riddick danced at the 15-yard line. Kelly pinballed through a handshake line that included NASCAR driver Kurt Busch. And freshman linebacker Troy Niklas, after his first start, declared to a teammate with a mix of sarcasm and relief: "We won!"